A fluid dynamic bearing device rotatably supports, with oil films formed in bearing gaps, a member on a rotary side (a shaft member, for example) with respect to a member on a fixation side. The fluid dynamic bearing device features high-speed rotation, excellent rotational accuracy, quietness, and the like. In recent years, by taking advantage of those features, the fluid dynamic bearing device is suitably used as a bearing device for a motor to be mounted to various electrical apparatuses such as information apparatuses. Specifically, as a bearing device for a motor, the fluid dynamic bearing device is suitably used in the following: a spindle motor for a magnetic disk drive such as an HDD, an optical disk drive for a CD-ROM, CD-R/RW, DVD-ROM/RAM, or the like; a polygon scanner motor of a laser beam printer (LBP); or a fan motor for a PC or the like.
For example, JP 2003-239974 A (Patent Document 1) discloses a fluid dynamic bearing device used while being incorporated in a spindle motor for a disk drive, which includes a housing, a bearing sleeve fixed to an inner periphery of the housing, a shaft member inserted along an inner periphery of the bearing sleeve, and radial bearing portions with which the shaft member is supported in a radial direction by oil films formed in radial bearing gaps between an inner peripheral surface of the bearing sleeve and an outer peripheral surface of the shaft member, the oil films being formed in accordance with a relative rotation of the bearing sleeve and the shaft member. In the fluid dynamic bearing device, for the purpose of reducing the number of components and the number of assembly steps, the housing is formed as a molded product having a bottomed cylindrical shape (cup shape) with one open end and another end closed with a bottom portion integrally provided.